Numerical Simulation of Characteristics of CEX Ions in Ion Thruster Optical System

• Published in: Chinese journal of aeronautics Vol. 23; no. 1; pp. 15 - 21
• Main Authors: Lingwei, Zhong, Yu, Liu, Juan, Li, Zuo, Gu, Haocheng, Jiang, Haixing, Wang, Haibin, Tang
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2010
• Subjects: Accelerators; charge exchange collision; Computer simulation; electric propulsion; Erosion; Ion exchangers; ion optical system; ion propulsion; Ion thrusters; Mathematical models; Monte Carlo methods; particle simulation; Sputtering; 数值模拟; 电荷交换; 离子光学系统; 离子加速器; 离子发动机; 离子推进器; 离子碰撞; electric propulsion; ion propulsion; ion optical system; particle simulation; charge exchange collision
• ISSN: 1000-9361
• DOI: 10.1016/s1000-9361(09)60182-5

Charge exchange （CEX） ions could inflict severe damages on the ion thruster optical system. This article is aimed at investigating the characteristics of the CEX ions and their influences upon the optical system by means of particle-incell（PIC） ion simulation and Monte Carlo collision（MCC） methods. The results from numerical simulation indicate that despite the fact that CEX ions appear in the entire beamlet region near the ion optical system, the ones that present themselves downstream of the accelerator grid have good reason for attracting more attention. As their trajectories are significantly affected by the local electric field, a great number of CEX ions are accelerated toward grids resulting in sputtering erosion. When the influences of the CEX ions are considered in the nulnerical simulation,there could hardly be observed augments in the screen grid current,but the accelerator grid current increases from zero to 1.4% of the beamlet current. It can be understood from the numerical simulation that the CEX ions formed in the region far downstream of the accelerator grid should be blamed for the erosion on the downstream surface of the accelerator grid.